We consider the turbulence generated by an oscillating grid near the surface and its influence on the vertical distribution of millimetric buoyant particles. First, we performed the detailled description of this turbulence through PIV measurements in order to obtain vertical profiles of characteristics quantities of the flow (integral and Kolmogorov scales, turbulent kinetic energy, dissipation rate). Secondly, we investigate the influence of surface turbulence on the plastic suspension, using particles with a size between the integral scale and the Kolmogorov one. We compare our results with existing models in the context of the plastic pollution in the ocean.